Process of removing paint from cylinders and containers



Nov. 26, 1929. H. w. COLE ET AL PROCESS OF REMOVING PAINT FROM CYLINDERS AND CONTAINERS Filed NOV. 17, 1924 V Emma Items 7% $2 Patented Nov. 26, 1929 UNITED STATES PATENT. OFFICE HARRY W. COLE, NEW ROCHELLE, NEW YORK, AND MALCOLM W. MGLAREN, OF

DETROIT, MICHIGAN, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE LIQUID CAR- IBONIC CORPORATION, OE NEW YORK, N. Y., A CORPORATION OF DELAWARE PROCESS OF REMOVING PAINT FROM CYLINDERS AND CONTAINERS Application filed November 17, 1924. Serial No. 750,359.

This invention relates to a process for cleaning substantially cylindrical articles, and more particularly for removing paint or the like from such articles as cylindrical containers for com ressed gases, although, of course, it is not confined to use for this specific purpose but may be used for cleaning other articles of similar t pe or shape.

It is an object o he invention-to provide a process which will clean these articles, especially to remove paint from their outer surfaces, which will clean them much more rapidly and thoroughly than the methods now generally used and will, therefore, perform this operation at a much less cost.

It is also an object of the invention to so arrange the mechanism for carrying out the process that the articles will pass through the cleaning solution under the action of gravity, which movement will also cause the surfaces ofthe adjacent cylinders to rub together to assist in the cleaning operation so that no mechanical feeding, rubbing or scraping device will be necessary, and therefore, the cost of operation will be reduced to a minimum.

With theforegoing and other objects in view, we have devised the construction illustrated in the accompanying drawing forming a part of this specification, similar reference characters being employed throughout the various figures to indicate corresponding elements. In this drawing,

Fig. 1 is a longitudinal section through one form of device for carrying out my improved process. 7

Fig. 2 is a top'plan view thereof with the cover, however, removed, and

Fig. 3 is a transverse section substantially on line 33 of'Fig. 1.

Heretofore it hasbeen a very diflicult and expensive operation to remove paint from the outer surface of cylinders, such as the cylindrical metal containers dsed-fo'r transporting and storing compressed gases. Various methods were used, such as scraping off the paint with special knives, burning it off with torches, and in some more elaborate mechanical methods attempts have been made to simplify the process by inverting the cylinders one or more at a time in baths of heated almay be more thoroughly cleaned at a much less cost.

In carrying out our process we provide a tank 10 of any suitable size depending upon the sizes of the cylinders to be cleaned and the operation required which is adapted to hold a suitable solution 11 for softening the coating on the surfaces of the cylinders. These cylinders are relatively heavy, the average weight being about 110 pounds. When material to be removed from the cylinders is a coating of paint, the solution should con tain a paint softening material, and the cylinders indicated at 12 are passed through this solution at the proper speed to give the solution an opportunity to act, and at the same time the cylinders are kept in contact and are rotated so that their surfaces will rub together to scrape off the softened paint so that as they leave the tank they are thoroughly cleaned. We have provided a mechanism which employs the force of gravity to pass the cylinders through the solut on, maintain them in contact and also causerelative rotary movement of the cylinders to-give the rubbing effect desired.

This operation is secured by providing a downwardly inclined runway 13 extendlng into one end ofthe tank, preferably leading from a suitable platform 14 of the desired height. At the lower end. of this runway is a longitudinally extending runway 15 below the surface'of the solution, and an upwardly inclined'runway 16 leads from the opposite end of this latter runway and out the opposite end of the tank. These various runways may be formed of any suitable construction, such as T-rails as shown, and the runway 13 is higher than the runway 16 so, that as the cylinders 12 are rolled from the platform 14 onto the runway 13 the greater weight of the cylinders on this runway will cause them to roll down this runway into the solution,along the intermediate runway 15 in this solution and outwardly from the tank by rolling up the runway 16. It will be apparent that by continuously feeding cylinders to the top of the runway 13 there will be a continuous movement of the cylinders through the solution in the tank and will be more thoroughly and quickly removed because it is scraped off by this rubbing action as soon as it becomes sufficiently softened by the solution, allowing the solution to gain access to the harder coating underneath. In other words, the coating is removed as it is softened and the softening solution is not required to penetrate through a thick coating. Furthermore this movement of the cylinders causes a continuous agitation of the solution so that fresh solution is constantly brought into contact with the coating to be softened and removed, which still further facilitates the cleaning operation.

Means is provided whereby the speed at which the cylinders move through the solution may be controlled and varied at will. A convenient means of doing this is to hinge the opposite ends of the intermediate runway 15 to the lower ends of the inclined runways 13 and 16 as shown at 17 and 18 respectively, and to provide means whereby this intermediate runway may be raised orlowered to vary the inclinations of the inclined runways. For this purpose upright struts 19 may be provided on opposite sides of the tank and the rails 20 of the intermediate runway mounted on rods 21 extending between uprights 22. These uprights may be secured to the struts 19 by suitable pins 23 pasing through ,the uprights and projecting into openings in the struts, of which there are a plurality at different heights. Thus by removing the pins either end of the runway may be raised or lowered and secured in the proper position by reinserting the pins. In this manner the inclination of the runways 13 and 16 may be varied and the speed at which the cylinders move through the solution regulated accordingly.

Guide means is provided above the cylinders on the intermediate runway to prevent their moving upwardly under the action of the pressure on o posite sides thereof and also the buoyant e ect of the solution. This may be similar T-rails 24 extending horizontally above the cylinders and mounted on transverse bars 25 carried by upri ht members 26 which are adjustable up an down on the uprights 22 and held in adjusted positions by suitable pins 27. By this arrangement these upper guides may be moved to the proper distance above the lower rails 20 to accommodate any given size of cylinder,

and when adjusted to any particular size of cylinder will move with the lower rails when they are adjusted to vary the inclinations of the inclined runways. A cover 28 may also be provided above the upper guides to more thoroughly enclose the solution and the mechanism.

Means is also provided for heating the alkali or other solution provided for softening the coating, such as a steam coil 29, supplied from any suitable source of supply by a pipe 30, and this coil is provided with any suitable form of trap 31 for condensation. A tank 32 is provided at the outlet end of the runway 16 and contains water or other suitable solution to remove the alkali from the cylinders as they pass out of the tank 10 over the top of the runway 16. The water from this tank may be kept fresh from av suitable source of supply through a pipe 33 and the level maintained by the drain 34.

The following is given as an exam le of an apparatus for carrying out this met od. In an apparatus which we have constructed and used the tank is about fifteen feet long, eighteen inches deep and sixty inches wide.

As indicated above the average weight of the cylinders to be cleaned is about 110' pounds. In the apparatus as used the cylinders travelled about one foot per minute and the time they remained in the solution was about fifteen minutes, so that after the first fifteen minutes,

which is taken to completely fill the tank, one cylinder is placed on the runway and one leaves the tank each minute, thus making it a one cylinder per minute outfit. The angle of the inclines 13 and 16 is about 30 de rees to the horizontal. The height of the plat orm 14 from the bottom of the tank is about 35 inches. We secured the best results with the scription that the device is extremely simaplle y in construction and requires no mechanic moving parts, so that the cost of operation is reduced to a minimum. Furthermore, that the weight of the cylinders maintains them in close contact while in the solution so that the rubbing effect caused by the rotation of the .cylindersas they pass along the runways thoroughly removes the coating softened by the solution. Furthermore, the operation is continuous. The action is substantially automatic as all that is necessary is to roll the cylinders to the upper end of the'inclined runway 13 from the platform, and the head or additional weight is sufficient to cause the movement of the cylinders into and through the tank and out the lower inclined runway 16. It has been found in practice that the scraping and rubbing of the cylinders together during this movement and the agitation of the solution also caused by this movement promotes in a most remarkable fashion 15 the speed with which the cleaning may be eflected. Whereas in the most eflicient prior apparatus known to us the maximum capacity was sixty cylinders in ten hours in actual practice we can with our apparatus remove paint from eighty cylinders in four hours,

ut this capacity may be increased by increasing the size of the apparatus vHaving thus set forth the nature of 'ourinvention, what we claim is:

The process of removing paint and similar coatings from substantially cylindrical articles which consists in passing the articles into, through, and out of a paint softening solution as a continuous operation with their outer surfaces in contact, and rotating said articles while in the solution to cause a relative movement and rubbing between said surfaces as the articles move through the solution.

In testimony whereof we aflix our signatures.

HARRY W. COLE. MALCOLM W. MoLAREN. 

